Document 4207Q258 V3.00 January 2018
Page 26 of 30
Chirascan Couette Cell LD Accessory User Manual
3.5
Making circular dichroism measurements using the accessory
The Couette cell accessory is designed primarily for making LD measurements, but circular dichroism (CD)
measurements can be made using the accessory if necessary.
3.5.1 Making a CD measurement using the Couette cell
To make a circular dichroism measurement on a sample while shearing, follow the procedure above but with
Circular dichroism selected from the drop-down list on the
Signal
panel (Figure
). An important point to
note is that any LD response will distort the CD signal, giving an incorrect CD measurement. Always check
that there is no LD response when making a CD measurement while shearing.
3.5.2 Making a CD measurement using a rectangular cell
CD measurements can be made using a short pathlength (
≤1 mm) rectangular cell without removing the whole
accessory from the spectrometer; a 0.5 mm pathlength cell is recommended, to correspond with the pathlength
of the Couette cell.
Remove the Couette cell stator and rotor so that the accessory appears as in Figure
. Replace with the
adaptor shown in Figure
, and mount as shown in the same figure.
Figure 3.12: Rectangular cell adaptor (left) and mounted with a cell in place (right)
